With conventional lighting systems, when numerous light sources are provided in a hall for example, the light intensities of the light sources are adjusted individually to set the illumination appropriately for numerous locations inside the hall. With such a technique, it is necessary repetitively adjust each of the light sources using trial and error to set the illumination at a predetermined position to a desired value. Also, it is necessary to adjust the light intensity of each of the light sources regularly or for each performance in accordance with the changing over time of the illumination of the lamps. Similarly, adjustments are necessary when the illuminant has degraded and is replaced. And in conference rooms or the like, the immediate optimal illumination varies when outside light from a window varies.
On the other hand, systems capable of sensing the condition of each light source, detecting malfunctions, and remotely controlling the respective illuminations of the light sources are known as intelligent lighting systems (for example see Shomei Shisutemu no Chitekika Sekkei (Incorporating Greater Intelligence in the Design of Lighting Systems), Mitsunori Miki and Takafumi Kozai, Doshisha University, Science and Engineering Research Report, July 1998, Volume 39, No. 2, pp 24-34).
However, even with systems such as that described in the aforementioned document, in order to set a desired illumination in desired locations in audience seats and on stage, trial and error and adjustments have been necessary as with conventional systems.
On the other hand, although commonly known automatic control may be used to adjust a single point of illumination of a single light source to a predetermined target value, in cases such as where a plurality of light sources are used and the overall illumination distribution in a room is to be set to a desired condition, it has not been easy to solve the issues of adjusting a plurality of control targets to set and maintain a condition in which a plurality of target values are met.